U.S. patent application number 16/180676 was filed with the patent office on 2019-03-07 for jarring apparatus.
This patent application is currently assigned to Rotojar Limited. The applicant listed for this patent is Rotojar Limited. Invention is credited to Peter Barnes Moyes.
Application Number | 20190071945 16/180676 |
Document ID | / |
Family ID | 48537501 |
Filed Date | 2019-03-07 |
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United States Patent
Application |
20190071945 |
Kind Code |
A1 |
Moyes; Peter Barnes |
March 7, 2019 |
Jarring Apparatus
Abstract
A downhole jarring apparatus for use in jarring an object in a
bore comprises a first jarring portion including a first impact
surface and a second jarring portion including a second impact
surface. The apparatus includes a rotatable jarring arrangement
operable to translate a rotational drive movement to cause relative
axial movement of the first and second impact surfaces to establish
axial impact therebetween.
Inventors: |
Moyes; Peter Barnes;
(Banchory, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rotojar Limited |
Banchory Aberdeenshire |
|
GB |
|
|
Assignee: |
Rotojar Limited
Banchory Aberdeenshire
GB
|
Family ID: |
48537501 |
Appl. No.: |
16/180676 |
Filed: |
November 5, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14778428 |
Sep 18, 2015 |
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PCT/GB2014/051212 |
Apr 17, 2014 |
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16180676 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 31/113 20130101;
E21B 31/107 20130101; E21B 31/005 20130101 |
International
Class: |
E21B 31/107 20060101
E21B031/107 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 19, 2013 |
GB |
1307112.1 |
Claims
1. A downhole jarring apparatus for use in jarring an object in a
bore, comprising: a first jarring portion including a first impact
surface; a second jarring portion including a second impact
surface; and a pressurising apparatus operable by a rotational
drive movement to cause relative axial movement of the first and
second impact surfaces to establish axial impact therebetween.
2. The downhole jarring apparatus according to claim 1, wherein the
pressurising apparatus provides fluid communication of an actuating
fluid between first and second fluid reservoirs, for use in
facilitating impact between the first and second impact
surfaces.
3. The downhole jarring apparatus according to claim 2, wherein the
pressurising apparatus is configured to vary pressure between the
first and second jarring portions to facilitate relative axial
movement between the first and second impact surfaces.
4. The downhole jarring apparatus according to claim 2, wherein the
pressurising apparatus is configurable between: a pressurising
stage, wherein the second fluid reservoir is pressurised; and
depressurising stage, wherein the second fluid reservoir is
depressurised.
5. The downhole jarring apparatus according to claim 4, wherein the
pressurising apparatus is configurable in the pressurising stage to
cause relative axial separation of the first and second impact
surfaces by communicating actuating fluid from the first fluid
reservoir to the second fluid reservoir to pressurise the second
fluid reservoir, thereby forcing the first and second impact
surfaces to separate relatively in an axial direction.
6. The downhole jarring apparatus according to claim 4, wherein the
pressurising apparatus is configurable in the depressurising stage
to depressurise the second fluid reservoir by communicating
actuating fluid from the second reservoir to the first reservoir
via a pressure release system, thereby permitting the first and
second impact surfaces to move axially together such that an impact
force is generated therebetween.
7. The downhole jarring apparatus according to claim 2, wherein the
pressurising apparatus comprises a valve system.
8. The downhole jarring apparatus according to claim 7, wherein the
valve system is configured to prevent fluid communication between
the first and second reservoirs, thereby permitting
re-pressurisation of the second reservoir according to rotational
drive movement of the pressurising apparatus.
9. The downhole jarring apparatus according to claim 4, wherein the
pressurising apparatus is configured to cycle between the
de-pressurising stage and the pressurising stage to facilitate
cyclical impact between the first and second impact surfaces.
10. The downhole jarring apparatus according to claim 2, wherein
the pressurising apparatus is configurable in a disabled stage,
wherein the pressurising apparatus is prevented from providing
fluid communication between first and second fluid reservoirs.
11. The downhole jarring apparatus according to claim 1, comprising
a fluid cavity for receiving an actuating fluid.
12. The downhole jarring apparatus according to claim 11, wherein
the pressurising apparatus retains pressure in the cavity during
axial separation of the first and second impact surfaces.
13. The downhole jarring apparatus according to claim 11, wherein
the pressurising apparatus is configured to depressurise the cavity
to permit the first and second impact surfaces to be impacted
together.
14. The downhole jarring apparatus according to claim 11, wherein
the pressurising apparatus is configured to pressurise and
depressurise the cavity, and wherein the apparatus is
reconfigurable between: a first configuration in which the first
and second impact surfaces are prevented from impacting each other;
a second configuration in which the first and second impact
surfaces are subsequently impacted together through
depressurisation of the cavity; and a third configuration in which
the first and second impact surfaces are subsequently axially
separated through pressurisation of the cavity.
15. The downhole jarring apparatus according to claim 14, wherein
the apparatus is configured to cyclically pressurise and
depressurise the cavity to permit subsequent impacts between the
first and second impact surfaces.
16. The downhole jarring apparatus according to claim 1, wherein
the rotatable jarring arrangement is configured to receive
rotational drive from a rotational drive mechanism.
17. The downhole jarring apparatus according to claim 1, wherein
the apparatus is configurable from a disabled configuration in
which the impact surfaces are prevented from being axially impacted
together, and a jarring configuration in which the impact surfaces
are permitted to be axially impacted together and generate an
impact force therebetween.
18. The downhole jarring apparatus according to claim 17, wherein
the apparatus is reconfigurable from the jarring configuration to
the disabled configuration such that the apparatus is
re-settable.
19. A method for use in jarring an object in a bore, comprising:
engaging a downhole jarring apparatus according to claim 1 with the
object; and applying a rotational drive movement to or within the
apparatus to cause relative axial movement and impact between first
and second impact surfaces within the jarring apparatus.
20. A downhole jarring apparatus for use in jarring an object in a
bore, comprising: first and second impact surfaces configured to be
axially separated and impacted together to generate a jarring
force; a cavity configured to be pressurised during axial
separation of the first and second impact surfaces; and a rotatable
jarring arrangement operable by a rotational drive movement to
depressurise the cavity to permit the first and second impact
surfaces when axially separated to be axially impacted together.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application is a Divisional application of U.S.
application Ser. No. 14/778,428, filed Sep. 18, 2015, which is a
National Phase of PCT/GB2014/051212, filed Apr. 17, 2014; which
claims priority under 35 U.S.C. .sctn. 119 to Great Britain
Application No. 13071121, filed on Apr. 19, 2013, in the Great
Britain Property Office (GBPO), the entire contents of each of
which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a jarring apparatus for use
in jarring an object within a bore, such as a wellbore.
BACKGROUND TO THE INVENTION
[0003] Many industries require objects such as tools to be deployed
through bores, such as wellbores in the oil and gas exploration and
production industries, and there is always the risk of such objects
becoming stuck in the bore. For example, wellbores may be drilled
into the earth using long drill strings, which may become stuck,
for example due to frictional engagement with the bore wall, due to
collapse of the bore, due to differential pressures between the
bore and surrounding formation pushing the drill string against a
bore wall, due to binding with drill cuttings, or the like.
Successful recovery of the drill string is of extreme importance
and value to a drilling operator as the cost of failure to recover
the tools and the well could run into several tens of millions of
pounds.
[0004] Current methods for recovering stuck objects include impact
tools known as jars which function to hammer or jar a stuck object.
Drilling jars are universally employed globally by companies in the
drilling and construction of oil and gas wells. However, current
jarring technology has not changed or evolved for several decades,
and is extremely limited in its functionality. For example,
existing jarring tools may be considered to be slow, imprecise,
hazardous, costly and damagingly large scale and slow rate.
[0005] Generally, a drilling jar is a mechanical device used
downhole to deliver an impact load to another downhole component
such as a bottom hole assembly (BHA). Known drilling jars operate
by storing energy in a drilling string, for example by applying
tension within the string, and suddenly releasing this energy to
cause two impact surfaces to move axially and strike each other,
creating an impact or jarring force within the drill string. This
conventional drilling jar technology is known as a `Linear Jarring`
method and offers limited functionality and presents several
significant drawbacks during its operation, such as: [0006] Each
impact has a high recoil force which reverberates back to the rig,
shaking and impacting the rig derrick and superstructure
detrimentally. [0007] Time between impacts is lengthy--up to 2
minutes between impacts. [0008] The inability to readily adjust the
magnitude of a generated jarring force, as this is conventionally
set at a predetermined value prior to the drilling jar being
deployed. [0009] Re-setting of the jar between impacts requires a
force to be applied to the jar and drill-string in the opposite
direction, consequently pushing the stuck drill-string back into
the problem portion of the well. [0010] High amplitude/low
frequency jarring (large impact force with long intervals between
impacts, which is a feature of linear jarring) is often the cause
of further hole collapse and can add to the problem which is trying
to be resolved. [0011] High amplitude/low frequency impact performs
poorly in freeing stuck pipe in clays and shales, which are a
common rock type to cause sticking of pipe and hole instability.
[0012] High amplitude/low frequency jarring performs poorly in
addressing stick-slip binding of a drill string, in which a single
jar only achieves a small slipping motion before the drill string
sticks again.
[0013] Various drilling jarring tools and methods are disclosed in,
for example, U.S. Pat. No. 7,882,906, U.S. Pat. No. 3,199,933, U.S.
Pat. No. 1,653,093, U.S. Pat. No. 1,653,094, U.S. Pat. No.
1,901,513, U.S. Pat. No. 2,146,454, U.S. Pat. No. 2,153,883, U.S.
Pat. No. 3,139,933, U.S. Pat. No. 4,890,682, U.S. Pat. No.
7,191,852, U.S. Pat. No. 4,576,229, WO 2009/134886 and U.S. Pat.
No. 6,845,818.
SUMMARY OF THE INVENTION
[0014] An aspect of the present invention relates to a downhole
jarring apparatus for use in jarring an object in a bore.
[0015] The apparatus may comprise an impact arrangement comprising
opposing impact surfaces. The apparatus may comprise a rotatable
jarring arrangement which is operable to translate a rotational
drive movement to cause axial impact between the impact
surfaces.
[0016] The apparatus may comprise multiple impact arrangements each
comprising opposing impact surfaces. The impact arrangements may be
operable simultaneously. The impact arrangements may be operable
independently of each other.
[0017] According to an aspect of the present invention there is
provided a downhole jarring apparatus for use in jarring an object
in a bore, comprising:
[0018] a first impact surface;
[0019] a second impact surface; and
[0020] a rotatable jarring arrangement operable to translate a
rotational drive movement to cause relative axial movement of the
first and second impact surfaces to establish axial impact
therebetween.
[0021] In use, the apparatus may be engaged with an object, such as
an object which has become stuck in a bore, and the first and
second impact surfaces axially impacted together by operation of
the rotatable jarring arrangement, thereby applying a jarring
effect to the object. As this jarring effect is achieved by a
rotational drive movement, the apparatus may be defined as a rotary
jarring apparatus. Furthermore, as this jarring effect is achieved
by a rotational drive movement, rather than a solely relative
linear motion, problems associated with prior art linear jars may
be at least partially addressed.
[0022] The first impact surface may be provided on a first jarring
portion, and the second impact surface may be provided on a second
jarring portion. The rotatable jarring arrangement may be
associated with at least one of the first and second jarring
arrangements.
[0023] The apparatus may be configured to assist in freeing a stuck
object to permit removal of the object from the bore, and/or to
permit further advancement of the object through the bore.
[0024] The apparatus may be configured to actuate or operate an
object within a bore. For example, jarring of an object by the
apparatus may cause the object to be actuated.
[0025] The apparatus may be configured for use within any suitable
bore. In one embodiment the apparatus may be configured for use
within a drilled bore, such as a drilled wellbore extending into
the earth, for example to extend to a subterranean formation. The
apparatus may be configured for use within an open or unlined
drilled bore. The apparatus may be configured for use within a bore
which is in the process of being drilled. The apparatus may be
configured for use within the bore of a tubing structure, such as
within a casing or liner tubing structure which lines a drilled
bore, within a pipe-line, such as a surface or sub-surface
pipe-line, or the like.
[0026] The apparatus may be configured to deploy an object in a
bore. In such an arrangement any sticking or jamming of an object
during such deployment may be addressed by the apparatus. In such
an arrangement the apparatus may be configured in a disabled
configuration during deployment of the object, with the apparatus
reconfigured into a jarring configuration when jarring is
required.
[0027] The apparatus may be configured to be engaged with an object
already present within a bore. That is, the apparatus may be run
into a bore, for example on a connected work string, until
engagement of an object is achieved, and then used to assist to
free said object.
[0028] The apparatus may be configured for use in jarring an object
positioned below the apparatus in a bore. Alternatively, or
additionally, the apparatus may be configured for use in jarring an
object positioned above the apparatus. It should be understood,
however, that the terms such as "upper", "lower", "above" and
"below" are not intended to only be limited with reference to a
vertical orientation. Instead, such terms should be assumed in
relation to the entry point of a bore, such that a region nearer to
an entry point may be defined as an upper region, and a region
further from an entry point may be defined as a lower region.
[0029] The apparatus may be configured to be self-jarring. That is,
the apparatus may be configured to provide a jarring force directed
at itself.
[0030] The apparatus may be configured to permit axial jarring in
one axial direction, such as an upwardly and downwardly direction.
The apparatus may be configured to permit axial jarring in opposing
axial directions, such as both upwardly and downwardly.
[0031] The magnitude of an axially applied force between the first
and second impact surfaces may dictate the magnitude of a generated
jarring force. The magnitude of the generated jarring force may be
readily adjusted and controlled by appropriate variation of the
applied axial force, for example by varying the tension and/or
compression within an associated work string. This may avoid the
limitations of prior art arrangements in which the jarring force of
a jarring tool may be typically set at a predefined value prior to
deployment of the tool, and cannot be varied while deployed.
[0032] The rotatable jarring arrangement may translate a rotational
drive movement to cause axial separation of the first and second
impact surfaces, and subsequent impact of the first and second
impact surfaces to generate an impact therebetween.
[0033] The rotatable jarring arrangement may be configured to
receive rotational drive movement from a rotational drive
mechanism.
[0034] The rotational drive mechanism may be configured separately
from the apparatus.
[0035] The apparatus may comprise a rotational drive mechanism.
[0036] The rotational drive mechanism may be coupled or otherwise
associated with the rotatable jarring arrangement and configured to
provide a rotational drive movement to the rotatable jarring
arrangement.
[0037] The rotational drive mechanism may comprise a work string.
In such an arrangement the rotatable jarring arrangement may be
configured to receive rotational drive movement from an associated
work string which may be coupled to the apparatus. In such an
arrangement the associated work string may be defined as a
rotatable work string.
[0038] The rotational drive mechanism may comprise a driving
component, for example, an electric motor, pneumatic motor,
hydraulic motor or the like.
[0039] The rotatable jarring arrangement may be at least partly
defined by or within one or both of first and second jarring
portions. The rotatable jarring arrangement may be interposed
between the first and second jarring portions. At least a portion
of the rotatable jarring arrangement may be defined by one or both
of the impact surfaces.
[0040] The rotating jarring arrangement may be at least partly
defined by a mechanism interposed between the first and second
jarring portions which may be formed and arranged to convert
relative rotating movement between the first and second jarring
portions to relative linear movement between the first and second
jarring portions. Such a mechanism may be provided remotely from at
least one impact surface. Such a mechanism may be incorporated
within at least one impact surface.
[0041] The rotatable jarring arrangement may be configured to
effect relative axial translation of the first and second impact
surfaces according to engagement of said surfaces and a rotational
drive movement.
[0042] The first and second impact surfaces may define respective
uneven surface profiles. The uneven surface profiles may be defined
by surface variations in the associated impact surfaces. The first
and second impact surfaces may be configured to be engaged and
rotated relative to each other, for example by relative rotation of
associated first and second jarring portions, established by a
rotational drive mechanism such that rotating sliding engagement of
the respective uneven surface profiles generates an impact force
therebetween.
[0043] The respective profiles of the first and second impact
surfaces may be configured to permit a rotational impact force to
be generated therebetween upon relative rotating sliding engagement
of the surfaces.
[0044] The apparatus may be configured to permit an axial force to
be applied between the first and second impact surfaces, at least
when the apparatus is in a jarring configuration, such that a
combination of the axial force and relative rotation applied
between the impact surfaces permits the respective profiles to
generate an impact force therebetween. The axially applied force
may function to press the first and second impact surfaces
together. The axially applied force may be established by a
connected work string. Such a connected work string may apply a
compressive or tensile axial force to establish an axial force
between the first and second impact surfaces.
[0045] Respective profiles of the first and second impact surfaces
may be configured such that during rotating sliding engagement of
the impact surfaces, portions of the surfaces become separated
against the action of an axially applied force, and separated
portions subsequently impacted together to generate the impact
force. Such separation against the action of the axial force may
permit energy to become stored to be subsequently released during
impact of the surface portions. In embodiments where an axial force
is applied between the first and second impact surfaces by a
connected work string, energy may become stored within the
connected work string, for example as tension or compression within
said work string.
[0046] Respective profiles of the first and second impact surfaces
may be configured such that separation of the impact surfaces
occurs over a first time period, and subsequent impact following
this separation occurs over a second time period which is shorter
than the first time period. Such an arrangement may permit an
increase in the impulse force which may be generated.
[0047] The profiles of the first and second impact surfaces may be
defined by ramp structures circumferentially distributed around the
impact surfaces, wherein rotatable interengagement of the ramp
structures permits axial separation and reengagement of the
surfaces. The profiles may be defined by teeth structures, such as
serrated teeth, ratchet teeth or the like. The profiles may be
defined by respective cam surfaces.
[0048] The rotatable jarring arrangement may comprise
inter-engaging surfaces provided separately or remotely from the
first and second impact surfaces, wherein the inter-engaging
surfaces cooperate upon relative rotation to provide relative axial
movement of the first and second impact surfaces to generate an
impact force therebetween. In such an arrangement the
inter-engaging surfaces may be provided between the first and
second jarring portions.
[0049] The rotatable jarring arrangement may comprise an engaging
member configured to engage with a circumferential surface. The
engaging member may be associated with one of the first and second
jarring portions, and the circumferential surface may be associated
with the other of the first and second portions. A jarring effect
may be achieved by relative rotation of the circumferential surface
and engaging member.
[0050] The circumferential surface may be defined by a
circumferential track. The circumferential track may comprise
surface variations, for example, undulations, teeth or the
like.
[0051] The circumferential surface may be configured in combination
with an additional, axially-separated circumferential surface to
define a slot therebetween. The slot may be configured to
accommodate the engaging member. The engaging member and the slot
may be configured to rotate relatively such that the engaging
member may be engaged with at least one of the circumferential
surfaces upon relative rotation of the engaging member and the
slot.
[0052] The circumferential track may be rotated by the rotating
drive movement.
[0053] The engaging member may be rotated or moved along a
circumferential path by a rotating drive movement.
[0054] The engaging member may be configured to be continuously
engaged with the circumferential track upon relative rotation of
the engaging member and the circumferential track. The engaging
member may comprise, for example, a pin, rod, plate or the
like.
[0055] Relative rotational movement of the circumferential track
and the engaging member may be achieved by rotating the engaging
member relative to the circumferential track, which may be
rotationally fixed within its associated jarring portion.
[0056] Relative rotational movement of the circumferential track
and the engaging member may be achieved by rotating the
circumferential track relative to the engaging member, which may be
rotationally fixed within its associated jarring portion.
[0057] Relative rotational movement of the circumferential track
and the engaging member may be achieved by rotating both the
engaging member and the circumferential track,
[0058] The engaging member may be configured to continuously engage
with the circumferential track upon relative rotation of the
engaging member and the circumferential track.
[0059] Relative rotational movement of the engaging member and the
circumferential track may translate the relative rotational
movement into relative axial movement of the first and second
impact surfaces to facilitate axial impact therebetween.
[0060] The engaging member may be configured to extend radially
from one of the first or second portions to engage with the track
associated with the other of the first or second portions. The
engaging member may extend outwardly from a central axis of the
first or second portions. The engaging member may extend inwardly
towards the central axis of the first or second portions.
[0061] The rotatable jarring arrangement may comprise a
pressurising apparatus such as a pump and/or compressor configured
to respond to or be driven by a rotating drive movement to provide
fluid communication of an actuating fluid between first and second
fluid reservoirs, for use in facilitating impact between the first
and second impact surfaces.
[0062] The pressurising apparatus may be configured to provide a
pressure differential between the first and second fluid
reservoirs.
[0063] The pressurising apparatus may be configured in a
pressurising stage, wherein the second fluid reservoir may be
pressurised.
[0064] The pressurising apparatus may be configured in a
de-pressurising stage, wherein the second fluid reservoir may be
de-pressurised.
[0065] The pressurising apparatus may be configured in a disabled
stage, wherein the pressurising apparatus may be prevented from
providing fluid communication between first and second fluid
reservoirs.
[0066] The pressurising apparatus may be configured in the
pressurising stage to cause relative axial separation of the first
and second impact surface. Upon pressurisation, actuating fluid may
be communicated from the first fluid reservoir to the second fluid
reservoir, thereby forcing the first and second impact surfaces to
separate relatively in an axial direction.
[0067] The pressurising apparatus may be configured in the
de-pressurising stage to de-pressurise the second fluid reservoir.
The pressure in the second reservoir may be released upon reaching
a threshold limit, for example, a maximal relative separation of
the impact surfaces, at a pressure limit, or the like. Upon
pressure release, actuating fluid may be communicated from the
second reservoir to a first reservoir via a pressure release
system. A conduit, flow path or the like may be selectively
provided for communication of actuating fluid from second reservoir
to the first reservoir. A valve system may be configured to
maintain relative pressurisation of the first and second
reservoirs, until the threshold limit may be achieved.
[0068] When provided in the de-pressurisation stage the second
reservoir may de-pressurise by communicating actuating fluid from
the second reservoir to the first reservoir, thereby permitting the
first and second impact surfaces to move axially together such that
an impact force may be generated therebetween.
[0069] The valve system may be configured to prevent fluid
communication between the first and second reservoirs, thereby
permitting re-pressurisation of the second reservoir according to
rotational drive movement of the pressurising apparatus.
[0070] The pressurising apparatus may be configured to cycle
between the de-pressurising state and the pressurising state to
facilitate cyclical impact between the first and second impact
surfaces.
[0071] The pressurising apparatus may be configured to generate
multiple impacts upon subsequent cycles of pressurisation and
de-pressurisation.
[0072] The rotatable jarring arrangement may comprise a rotating
lobe arrangement, wherein the rotating lobe arrangement may be
interposed between the first and second jarring portions, and
wherein the rotating lobe arrangement may be configured to be
rotated by the rotating drive movement for use in facilitating
impact between the first and second impact surfaces.
[0073] The rotating lobe arrangement may comprise a lobe, for
example, a cam, eccentric disc or the like, wherein the lobe may be
configured to be engaged with a lobe contact surface, and wherein
the lobe may be shaped to generate relative axial movement of the
first and second impact surfaces upon rotation of the lobe relative
to the lobe contact surface.
[0074] Rotation of the rotating lobe arrangement may facilitate
impact between the first and second impact surfaces by rotating
movement of the lobe relative to the additional surface.
[0075] The lobe may be configured to be frictionally engaged with
the lobe contact surface, such that when rotated relative to the
lobe contact surface the lobe translates in a direction, for
example, a circumferential direction.
[0076] The lobe may be configured to be slidably engaged with the
lobe contact surface, such that when rotated relative to the lobe
contact surface, the lobe remains in a relative static location,
for example, a relative static circumferential location.
[0077] The rotating lobe arrangement may comprise a plurality of
lobes.
[0078] The rotatable jarring arrangement may be configured to
generate at least one jar or jar event for a single full 360 degree
revolution of an associated rotating drive movement. Accordingly,
multiple revolutions of the rotating drive movement may be
configured to generate multiple jars. This arrangement may permit
multiple jars to be generated without requiring a complete
resetting of the apparatus as may be required in known linear
jarring tools.
[0079] The apparatus may be configured to generate multiple jars
for a single 360 degree revolution of the rotating drive
movement.
[0080] The jarring frequency of the apparatus may be dictated by
the relative rotational velocity of an associated rotating drive
movement, and the number of jars generated by the rotating drive
movement for a single relative rotation.
[0081] The provision of a jarring force by use of the rotating
drive movement may permit a higher jarring frequency to be
achieved. The ability to achieve such higher frequencies may permit
an object engaged with the apparatus to be effectively vibrated,
rather than only receive the effect of a single or infrequent
jarring force. This ability to effectively vibrate an object may
provide significant advantages. For example, a higher jarring
frequency or application of a vibratory force to any solid
particulate which is in contact with an object, for example due to
collapse of the bore, may result in a condition termed `Solid
Particulate Liquefaction`. This phenomenon essentially converts the
behaviour of the solid particles within the region of the object to
that of a liquid, reducing the shear strength of the solid and
allowing the object to be more readily freed from any bind with the
solid particles.
[0082] Furthermore, the ability to apply higher frequency jarring,
and optionally in combination with the ability to provide increased
control over the magnitude of the jarring force, may improve the
ability to address any stick-slip bind between an object and a bore
wall or collapsed bore wall. Conventional jars which deliver high
amplitude/low frequency jarring are typically unproductive in this
environment (particularly as the jar re-setting action often
counters any gain made).
[0083] The jarring frequency of the apparatus may be controlled by
controlling the rotational velocity of an associated rotating drive
movement. Such an arrangement may provide improved control of the
jarring frequency, for example by permitting the jarring frequency
to be infinitely varied. This improved control may provide a
significant improvement over known jarring tools in which the
jarring frequency is typically dictated or limited by the time
required to reset the tool.
[0084] The ability to readily control the jarring frequency, for
example in an infinitely variable manner, by controlling the
rotational velocity of an associated rotating drive movement may
permit a user to adjust the jarring frequency in accordance with
specific requirements.
[0085] The apparatus may be configured to provide a jarring
frequency of, for example, between 0 Hz and 20 kHz, for example
between 0.5 Hz and 5 kHz, for example between 0.5 Hz and 1 kHz,
such as between 0.5 Hz and 100 Hz, for example between 0.5 Hz and
20 Hz.
[0086] In one embodiment the ability to readily vary the jarring
frequency may permit an object engaged with the apparatus to be
vibrated at its resonant or natural frequency (or a selected
preferred harmonic frequency). This may allow the delivery of
impact loading to far higher levels than would be achievable using
conventional jars, yet with significantly reduced input forces.
Further, when vibrating at resonant or a harmonic frequency, an
elongate object, such as a tubing string, tool string or the like,
may be caused to oscillate (wobble) in a sinusoidal wave pattern
within the bore. This may assist greatly with reducing the level of
contact between the object and the sticking medium and will
significantly contribute to breaking any differential pressure type
sticking (differential sticking).
[0087] The ability to vary jarring frequency may permit the
apparatus to be used to provide a single jarring event.
[0088] The apparatus may comprise a plurality of rotatable jarring
arrangements.
[0089] The apparatus may comprise different types of rotatable
jarring arrangements to provide different jarring forces.
[0090] The apparatus may be configured to provide different jarring
forces with different characteristics, for example, in terms of
force amplitude, frequency or relative phase of said jarring
forces.
[0091] The apparatus may be configured such that each of the
rotatable jarring arrangements may be separately selected to
provide a jarring force with a different characteristic.
[0092] The apparatus may be configured to provide sequential
jarring forces by sequentially selecting the different rotatable
jarring arrangements.
[0093] The apparatus may be configured to provide jarring forces
such that the amplitude, frequency or phase of the jarring forces
may be varied to preferentially provide jarring forces, for
example, a higher frequency, lower amplitude jarring force to
disturb the stuck object in combination with a lower frequency,
higher amplitude jarring force to further disturb the stuck
object.
[0094] In some embodiments the apparatus may be provided in
combination with a monitoring system configured to monitor
properties associated with a jarring action, for example to permit
any resonant behaviour to be monitored and allow adjustment of the
jarring frequency and/or magnitude accordingly. Such a monitoring
system may comprise one or more sensors, such as accelerometers,
vibration sensors, acoustic sensors or the like.
[0095] The apparatus may be configurable from a disabled
configuration in which the impact surfaces are prevented from being
axially impacted together, and a jarring configuration in which the
impact surfaces are permitted to be axially impacted together and
generate an impact force therebetween. As the jarring effect of the
apparatus may thus only be achieved when in the jarring
configuration, the apparatus may be selectively activated to
provide jarring. That is, when the apparatus is configured in the
disabled configuration the jarring effect may be deactivated.
Accordingly, the apparatus may provide extended functionality when
in its disabled configuration, such as being able to deploy and/or
actuate or operate other components or objects, wherein such
functionality may be difficult or impossible when the apparatus is
configured in its jarring configuration.
[0096] When the apparatus is in the disabled configuration the
rotatable coupling between the first and second jarring portions
may permit torque to be transferred therebetween. Accordingly, in
this disabled configuration the first and second portions may be
rotated together, for example by a connected work string. Such
ability to transmit torque between the first and second portions
may permit the apparatus to be used to rotate an object engaged
with the apparatus.
[0097] The first jarring portion may be configured to be rigidly
coupled to a work string. The first jarring portion may be
configured to be directly coupled to a work string. The first
jarring portion may be configured to be indirectly coupled to a
work string, for example by use of an intermediate component or
structure interposed between the first jarring portion and work
string. The first jarring portion may comprise a connector
configured to permit connection with a work string. The connector
may comprise a threaded connector or the like.
[0098] The second jarring portion may be configured to engage an
object by abutting said object. The second jarring portion may be
configured to be coupled to an object. The second jarring portion
may be configured to be rigidly coupled to an object. The second
jarring portion may be configured to be directly coupled to an
object. The second jarring portion may be configured to be
indirectly coupled to an object, for example by use of an
intermediate component or structure interposed between the second
jarring portion and object. In such an arrangement a jarring force
generated within the apparatus may be transmitted to the object via
the intermediate component. The second jarring portion may comprise
a connector configured to permit connection with an object. The
connector may comprise a threaded connector or the like.
[0099] When the apparatus is connected to a work string, said
apparatus may be considered to form part of the work string.
[0100] When the apparatus is engaged or connected with an object,
the apparatus and engaged or connected object may become part of
the work string.
[0101] The work string may comprise any structure capable of being
secured to the apparatus and for being deployed through a bore. The
work string may comprise any structure capable of being rotated to
impart torque to or within the apparatus, for example to the first
jarring portion. The work string may comprise an elongate
structure. The work string may comprise a pipe or pipe structure,
such as multiple pipes or tubulars coupled together, coiled tubing
or the like.
[0102] The work string may comprise a drill string or a portion of
a drill string. In such an arrangement the apparatus may be
configured as a drilling jarring apparatus. The work string may
comprise one or more of drill pipe, drill collars, stabilisers and
the like.
[0103] The work string may comprise a prop shaft coupled to a
motor, such as a surface motor, downhole motor or the like, wherein
said prop shaft may function to transmit torque from such a motor
to or within the apparatus, such as to the first jarring
portion.
[0104] The object may comprise any object which is or may be
located within a bore. The object may comprise multiple components
secured together. The object may comprise a downhole tool. The
object may comprise a further work string. The further work string
may comprise a portion of a drill string.
[0105] The object may comprise a drilling assembly, such as a
bottom hole drilling assembly. The object may comprise a drill bit
for use in drilling the associated bore. In such an arrangement
when the apparatus is configured in a disabled configuration,
torque applied to the first jarring portion via a connected work
string may be transmitted to the second jarring portion and
subsequently to an associated drill bit secured or engaged with the
second jarring portion. Accordingly, the drill bit may be rotated
to drill the bore via torque applied by the work string. In the
event of the drill bit or any associated apparatus, such as any
associated bottom hole assembly, becoming stuck or jammed within
the bore, the apparatus may be reconfigured to the jarring
configuration such that further torque applied by the work string
may be used to generate the impact force and apply jarring to the
drill bit or associated apparatus. This may assist to free and/or
advance the drill bit and any associated apparatus.
[0106] In one embodiment the apparatus may be configured to be
secured within a drill string. The apparatus may be configured to
be interposed between different sections of a drill string. The
apparatus may be configured to form part of a drill string.
[0107] When the apparatus is configured in the jarring
configuration one of the first and second jarring portions may be
rotatably fixed, and the other of the first and second jarring
portions may be rotatable to permit relative rotation between the
impact surfaces. One of the first and second jarring portions may
be rotatably fixed by engagement with an object which is also
rotatably fixed, for example by being stuck within the bore.
[0108] When the apparatus is configured in the jarring
configuration one of the first and second jarring portions may be
axially fixed, for example by engagement with an object which is
also axially fixed, for example by being stuck in a bore. Such an
arrangement may permit an axial force to be applied between the
first and second jarring portions via a connected work string, for
example to establish an axial force between the first and second
impact surfaces.
[0109] The apparatus may be reconfigured towards the jarring
configuration by application of a predetermined force between the
first and second jarring portions. The predetermined force may
comprise a rotational force. The predetermined force may comprise
an axial force. The predetermined force may be generated by a
connected work string.
[0110] The rotating jarring arrangement may provide a finite
relative axial movement of the impact surfaces according to the
configuration of the rotating jarring arrangement. The finite
relative axial movement may restrict movement of the impact
surfaces and reduce any effective impact force therebetween. The
apparatus may comprise an internal tensioning mechanism to increase
any effective impact force. The internal tensioning mechanism may
be configured to provide tensioning or de-tensioning capabilities
to permit sufficiently rapid impact of the impact surfaces to
generate an impact force therebetween. The internal tensioning
mechanism may be configured to provide tensioning or de-tensioning
capabilities to prevent rapid impact of the impact surfaces.
Tension provided by an associated work string may operate the
internal tensioning mechanism.
[0111] When the apparatus is in the disabled configuration the
rotatable jarring arrangement may be configured to prevent relative
movement of the first and second impact surfaces to prevent an
impact between the impact surfaces. The apparatus may be configured
in the disabled configuration when the rotational drive movement is
prevented from rotating the rotatable jarring arrangement.
[0112] When the apparatus is in the disabled configuration the
rotatable jarring arrangement may be configured to permit relative
movement of the first and second impact surfaces while preventing
impact between the first and second impact surfaces. The apparatus
may be configured in the disabled configuration when the rotational
drive movement permits rotation of the rotatable jarring
arrangement.
[0113] When the apparatus is in the disabled configuration the
rotatable jarring arrangement may be configured to permit relative
movement of the first and second impact surfaces and engagement
between the first and second impact surfaces. In this disabled
configuration the engagement between the impact surfaces may not
generate a sufficient impact force therebetween to generate a
jarring effect.
[0114] In certain embodiments the apparatus may be configured such
that initial engagement of the impact surfaces during
reconfiguration of the apparatus towards the jarring configuration
generates an impact force between said impact surfaces. This may
permit an initial jarring force to be generated during
reconfiguration of the apparatus, which is then proceeded by the
rotary jarring effect of the first and second impact surfaces when
subsequently rotated relative to each other, for example.
[0115] The first and second impact surfaces may be axially
separated when the apparatus is in the disabled configuration. In
such an arrangement reconfiguration of the apparatus to the jarring
configuration may be achieved by establishing relative axial
movement of the first and second jarring portions to engage the
impact surfaces. In one embodiment such axial movement may be
permitted upon application of a predetermined axial force.
[0116] The first and second jarring portions may be configured to
be axially telescoped relative to each other. Such an arrangement
may permit the jarring portions to be moved axially relative to
each other, for example to reconfigure the apparatus from the
disabled configuration to the engaged configuration.
[0117] The first and second jarring portions may be configured to
be axially coupled together. Such an axial connection may permit
axial load to be transmitted between the first and second jarring
portions in at least one direction. For example, such an axial
connection may permit an axial load, such as an axial compression
load, to be transmitted to an object via the apparatus. In one
embodiment such an arrangement may permit weight to be applied to a
drill bit engaged with the second jarring portion.
[0118] The axial connection between the first and second jarring
portions may be releasable, for example to permit reconfiguration
of the apparatus. The axial connection between the first and second
jarring portions may be configured to be released upon application
of a predetermined force.
[0119] The apparatus may comprise a connection arrangement
configured to provide a releasable connection between the first and
second jarring portions, wherein release of the connection
arrangement may permit the apparatus to be configured between the
disabled and jarring configurations.
[0120] The releasable connection may be configured to be released
upon exposure to a predetermined force.
[0121] The connection arrangement may be configured to provide a
releasable rotatable connection between the first and second
jarring portions. The connection arrangement may comprise a spline
arrangement. The connection arrangement may comprise at least one
spline or equivalent structure mounted on the first jarring
portion, and at least one corresponding spline or equivalent
structure mounted on the second jarring portion. In such an
arrangement the splines may be arranged to be engaged when the
apparatus is in the disabled configuration, and disengaged when the
apparatus is in the jarring configuration. Such disengagement of
the splines may be achieved by relative axial movement of the first
and second jarring portions.
[0122] The connection arrangement may comprise a radial member
which extends radially between the first and second jarring
portions to provide a rotatable connection therebetween, wherein
said radial member may be configured to be disengaged with at least
one of the first and second jarring portions, for example upon
application of a predetermined force, such as a predetermined
torque.
[0123] The connection arrangement may comprise a frangible
component extending between the first and second jarring portions
and configured to be broken, for example sheared upon application
of a predetermined force.
[0124] The connection arrangement may comprise a clutch interposed
between the first and second jarring portions to provide a
rotatable connection therebetween. Deactivation of said clutch may
be achieved upon application of a predetermined torque between the
first and second jarring member. In some embodiments, in a first
clutch configuration a full rotatable connection may be achieved
between the first and second jarring portions. In a second clutch
configuration relative rotation between the first and second
jarring portions may be permitted. In the second clutch
configuration the clutch may be entirely or completely disengaged
such that the clutch does not interfere with relative rotation
between the first and second jarring portions. In other
embodiments, in the second clutch configuration the clutch may
provide a degree of torque drag. Such torque drag may permit
relative rotation of the first and second jarring portions during a
jarring operation, yet may provide an instantaneous rotatable
connection between the jarring portions, for example at the moment
of release of an object being jarred.
[0125] The connection arrangement may be configured to provide a
releasable axial connection between the first and second jarring
portions.
[0126] The releasable axial connection may comprise a radial member
which extends radially between the first and second jarring
portions, wherein said radial member may be configured to be
disengaged from at least one of the first and second jarring
portions, for example upon application of a predetermined force,
such as a predetermined axial force. Such a radial member may be
defined by a key member. A plurality of radial members may be
provided.
[0127] The connection arrangement may comprise a frangible
component extending between the first and second jarring portions
and configured to be broken, for example sheared, upon application
of a predetermined force, such as a predetermined axial force.
[0128] The connection arrangement may be configured to provide a
rigid axial connection such that relative axial movement of the
first and second jarring portions is prevented until the connection
is released.
[0129] The connection arrangement may be configured to provide a
flexible axial connection between the first and second jarring
portions. Such a flexible connection may permit a degree of
relative axial movement between the first and second jarring
portions prior to release of the axial connection. The flexible
axial connection may be configured to restrict relative axial
movement between the first and second jarring portions prior to
release of the axial connection. Such a flexible connection may
permit energy to become stored within the apparatus or associated
components, such as a connected work string and/or engaged object
for use in applying a jarring force between the first and second
impact members upon release of the axial connection.
[0130] The connection arrangement may comprise an elastic
arrangement, such as a spring arrangement, configured to be
deformed upon initial relative axial movement between the first and
second jarring portions prior to release of the axial connection.
This elastic arrangement may be configured to store energy within
the apparatus during initial relative axial movement between the
first and second jarring portions. Such energy may be utilised to
permit release of any axial connection, and/or to facilitate an
initial impact force between the first and second impact
surfaces.
[0131] The connection arrangement may define a triggering
arrangement to permit the apparatus to be triggered to be
configured from the disabled configuration to the jarring
configuration.
[0132] The connection arrangement may be configured to provide both
a releasable axial connection and a releasable rotary connection
between the first and second jarring portions. In one embodiment
release of the axial connection may permit the first and second
jarring portions to be moved axially relative to each other, with
this axial movement permitting the rotary connection to be
released, for example to permit initially engaging splines of the
first and second jarring portions to become disengaged, to permit a
clutch to be at least partially disengaged, to disengage radial
members or the like.
[0133] The apparatus may comprise a clutch assembly provided
between the first and second jarring portions. The clutch assembly
may be configured to establish a rotatable connection between the
first and second jarring portions upon release of a stuck object
which is engaged with the second jarring portion. This arrangement
may permit the object to be rotated immediately upon release or
unsticking which may assist in prevent the object from become stuck
again, for example to assist to ream the bore. The clutch assembly
may establish a predetermined drag torque between the first and
second jarring portions, wherein relative rotational movement of
the first and second jarring portions is permitted when this drag
torque is exceeded.
[0134] The apparatus may be reconfigurable from the jarring
configuration to the disabled configuration. Such an arrangement
may permit the apparatus to be re-settable.
[0135] An aspect of the present invention relates to a method for
use in jarring an object in a bore.
[0136] This method may be performed by use of an apparatus
according to any other aspect. Accordingly, any features and/or
described methods, options and functionality of the apparatus of
any aspect may be assumed to also relate to this method.
[0137] The method may comprise cause relative axial movement and
impact between first and second impact surfaces within a jarring
apparatus, wherein said axial movement is caused by a rotational
drive movement.
[0138] The method may comprise:
[0139] connecting a first jarring portion of a jarring apparatus to
a work string, wherein the first jarring portion includes a first
impact surface;
[0140] engaging a second jarring portion of the jarring apparatus
with an object, wherein the second jarring portion includes a
second impact surface; and
[0141] applying a rotational drive movement to a rotatable jarring
arrangement associated with at least one of the first and second
jarring portions to cause relative axial movement of the first and
second impact surfaces to establish axial impact therebetween and
thereby applying a jarring force to the object;
[0142] The method may comprise reconfiguring the apparatus from a
disabled configuration in which the first and second impact
surfaces are prevented from being axially impacted together to a
jarring configuration in which the first and second impact surfaces
are permitted to be axially impacted together to generate an impact
force therebetween.
[0143] When in the disabled configuration the impact surfaces may
be axially separated, wherein the method comprises moving the
impact surfaces axially relative to each other to establish
engagement of the first and second impact surfaces. The method may
comprise moving the first and second impact surfaces axially
relative to each other to generate an impact force
therebetween.
[0144] An aspect of the present invention relates to an apparatus
for use in jarring an object in a bore, comprising:
[0145] a first jarring portion including a first circumferential
impact surface defining an uneven surface profile; and
[0146] a second jarring portion including a second circumferential
impact surface also defining an uneven surface profile,
[0147] wherein the first and second impact surfaces are configured
to be rotated relative to each other such that rotating sliding
engagement of the respective uneven surface profiles generates at
least one impact force therebetween.
[0148] The first and second impact surfaces may be configured to be
axially moved relative to each other to engage the first and second
impact surfaces and generate a first impact force therebetween, and
to be subsequently rotated relative to each other such that
rotating sliding engagement of the respective uneven surface
profiles generates at least a second impact force therebetween.
[0149] An aspect of the present invention relates to a downhole
jarring apparatus for use in jarring an object in a bore,
comprising:
[0150] a first profiled impact surface; and
[0151] a second profiled impact surface,
[0152] wherein the first and second impact surfaces are configured
to be rotated relative to each other to cause circumferential
sliding engagement of the profiled surfaces to establish an impact
force between the first and second portions.
[0153] An aspect of the present invention relates to a jarring
apparatus for use in jarring an object in a bore, comprising:
[0154] a first jarring portion comprising a first impact surface
which defines a first circumferential profile; and
[0155] a second jarring portion comprising a second impact surface
which defines a second circumferential profile,
[0156] wherein the apparatus is configurable between a first
configuration in which the first and second impact surfaces are
axially separated and the first and second portions are rotatably
coupled together, and a second configuration in which the first and
second impact surfaces are axially moved together to be engaged and
the first and second portions are rotatably decoupled to permit
relative rotational movement therebetween to cause the
circumferential profiles of the engaged first and second impact
surfaces to create an impact force therebetween.
[0157] An aspect of the present invention relates to a jarring
apparatus for use in jarring an object in a bore, comprising:
[0158] a first impact surface; and
[0159] a second impact surface,
[0160] wherein a rotating drive movement is configured to rotate a
rotatable jarring arrangement to sequentially axially separate and
axially engage first and second impact surfaces, whereby engagement
of the first and second impact surfaces generates an impact force
therebetween.
[0161] Subsequent rotation of the rotating drive movement may
generate subsequent impact forces.
[0162] An aspect of the present invention relates to a jarring
apparatus for use in jarring an object in a bore, comprising:
[0163] an engaging member; and
[0164] a circumferential surface,
[0165] wherein the engaging member is configured to be engaged with
the circumferential surface, and wherein the engaging member and
circumferential surface is rotated circumferentially relative to
each other by a rotating drive movement to sequentially axially
separate and axially engage first and second impact surfaces,
whereby engagement of the first and second impact surfaces
generates an impact force therebetween.
[0166] Subsequent rotation of the rotating drive movement may
generate subsequent impact forces.
[0167] An aspect of the present invention relates to a jarring
apparatus for use in jarring an object in a bore, comprising:
[0168] a first impact surface;
[0169] a second impact surface; and
[0170] a pressurising apparatus configured to pressurise and/or
de-pressurise a cavity,
[0171] wherein the apparatus is re-configurable between a first
configuration in which the first and second impact surfaces are
prevented from impacting each other, and a second configuration in
which the first and second impact surfaces are subsequently
impacted together through de-pressurisation of the cavity, and a
third configuration in which the first and second impact surfaces
are subsequently axially separated through pressurisation of the
cavity.
[0172] The apparatus may be configured to cyclically pressurise and
de-pressurise the cavity to permit subsequent impacts between the
first and second impact surfaces, thereby providing a jarring
effect.
[0173] An aspect of the present invention relates to a jarring
apparatus for use in jarring an object in a bore, comprising:
[0174] a first jarring portion comprising a first impact surface;
and
[0175] a second jarring portion comprising a second impact
surface;
[0176] wherein a rotating lobe arrangement is configured to engage
with a lobe contact surface, whereupon rotation of the rotating
lobe arrangement by a rotating drive movement causes relative axial
movement of the first and second impact surfaces to generate an
impact force therebetween.
[0177] Subsequent rotation of the rotating drive movement may
generate subsequent impact events thereafter.
[0178] It should be understood that one or more features defined in
relation to one aspect may be provided in combination with any
other aspect.
BRIEF DESCRIPTION OF THE DRAWINGS
[0179] These and other aspects of the present invention will now be
described, by way of example only, with reference to the
accompanying drawings, in which:
[0180] FIG. 1 is a diagrammatic illustration of a jarring apparatus
according to an embodiment of the present invention, wherein the
apparatus is shown in partial cut-away and configured in a disabled
configuration;
[0181] FIG. 2 is a diagrammatic illustration of the jarring
apparatus of FIG. 1, shown in a jarring configuration;
[0182] FIGS. 3a and 3b illustrate a sequential operation of a
jarring apparatus according to a further embodiment of the present
invention;
[0183] FIGS. 4a to 4c illustrate a sequential operation of a
jarring apparatus according to a further embodiment of the present
invention;
[0184] FIGS. 5a and 5b illustrate a sequential operation of a
jarring apparatus according to a further embodiment of the present
invention;
[0185] FIG. 6a is an axial view of a rotatable jarring arrangement
of the jarring apparatus in FIGS. 5a and 5b; and
[0186] FIG. 6b is a sequence of side views of a rotating lobe
arrangement of the jarring apparatus in FIGS. 5a and 5b during a
rotation cycle.
DETAILED DESCRIPTION OF THE DRAWINGS
[0187] A jarring apparatus, generally identified by reference
numeral 10, is illustrated in FIG. 1, with a section partially
cut-away to reveal internal features. The apparatus 10 is presented
in a disabled configuration in FIG. 1. The apparatus 10 may be
reconfigured to a jarring configuration, as illustrated in FIG.
2.
[0188] The apparatus 10 may be utilised to provide a jarring force
to any object located within a bore, for example to permit freeing
of the object, to permit actuation of the object or the like.
However, for the purposes of the present description the apparatus
is for the exemplary use of providing a jarring force to a bottom
hole drilling assembly 14, which is provided in the form of a lower
drilling string which carries drilling equipment, including a drill
bit (not shown).
[0189] The apparatus 10 comprises a lower connector 16 which
facilitates a rigid connection with the drilling assembly 14.
Further, the apparatus 10 comprises an upper connector 18 which
permits a rigid connection with a drill string 20 for use in
deploying the apparatus 10 and connected drilling assembly 14 into
a bore, and for applying torque and weight to the drilling assembly
14 to permit the bore to be drilled and advanced. The drill string
20 will typically include a combination of drill pipe and drill
collars.
[0190] The apparatus 10 includes a first or upper jarring portion
22 which is connected with the drill string 20 via connector 18,
and a second or lower jarring portion 24 which is connected with
the bottom hole drilling assembly 14 via connector 16. As will be
described in more detail below, the upper and lower jarring
portions 22, 24 are configurable between a disabled configuration
(FIG. 1) in which weight and torque may be transmitted between the
drill string 20 and drilling assembly 14 to advance the bore, and a
jarring configuration (FIG. 2) in which a jarring force may be
generated therebetween to be applied to the drilling assembly 14,
for example to assist in freeing this assembly in the event of
becoming stuck within the bore.
[0191] The upper jarring portion 22 includes a mandrel 26 which is
received within a sleeve portion 28 of the lower jarring portion
24, wherein this mandrel 26 includes an impact member 30 which
includes a circumferential impact surface 32 defined by a number of
circumferentially arranged teeth 34. The sleeve 28 of the lower
jarring portion 24 includes a corresponding impact member 36 which
also includes a circumferential impact surface 38 defined by a
number of circumferentially arranged teeth 40. The impact member 30
and corresponding impact member 36 make up a rotatable jarring
arrangement 37, wherein the rotatable jarring arrangement 37
provides a jarring force, as required.
[0192] The apparatus 10 comprises a releasable axial connection
arrangement 41 which functions to provide a releasable axial
connection between the jarring portions 22, 24. This axial
connection arrangement 41 permits the jarring portions 22, 24 to be
axially secured together when the apparatus 10 is in the disabled
configuration of FIG. 1, and be axially decoupled to permit
reconfiguration towards the jarring configuration, as in FIG. 2. As
will be described in further detail below, in the present
embodiment this axial connection arrangement 41 also functions as a
triggering mechanism to permit the apparatus 10 to be reconfigured
towards the jarring configuration.
[0193] The axial connection arrangement 41 is provided by a
shoulder 42 on a lower end of the mandrel 26, a release ring 44,
and a spring member 46 which extends between the shoulder 42 and a
release ring 44. When in the disabled configuration, as shown in
FIG. 1, the release ring 44 is rigidly secured to the sleeve 28 of
the lower jarring portion 24 via a number of releasable keys 48.
The connection arrangement 41 permits the jarring portions 22, 24
to be axially secured together in the disabled configuration such
that the impact members 30, 36 are axially separated and the
respective impact surfaces 32, 38 are disengaged. As will be
described in further detail below, the axial connection arrangement
41 may be released upon application of a predetermined axial force,
applied via the drill string 20, which causes the keys 48 to
release and decouple the release ring 44 from the sleeve 28.
[0194] The apparatus 10 further comprises a releasable rotary
connection arrangement 50 which permits the jarring portions 22, 24
to be rotatably connected together when the apparatus 10 is in the
disabled configuration of FIG. 1, and rotatably decoupled when the
apparatus is in its jarring configuration of FIG. 2. This rotary
connection arrangement 50 permits the transmission of torque
between the jarring portions 22, 24 when the apparatus 10 is in the
disabled configuration.
[0195] The rotary connection arrangement 50 comprises a plurality
of circumferentially distributed and axially extending spline
members 52 provided on the upper jarring portion 22, and a
plurality of corresponding spline members 54 provided on the lower
jarring portion. When the respective spline members 52, 54 are
intermeshed, as in FIG. 1, a rotatable coupling between the jarring
portions 22, 24 is achieved. This rotatable coupling may be
released by axially separating the jarring portions 22, 24 to
disengage the splines 52, 54, as shown in FIG. 2. Such axial
separation may be permitted following release of the axial
connection arrangement 41, as described in more detail below.
[0196] However, in some embodiments the separate rotary connection
arrangement 50 may not be essential, and the rotary connection may
be achieved by the axial connection arrangement 41. For example,
the keys 48, when extended, may permit torque to be transferred
between the jarring portions 22, 24. As such, the separate spline
arrangement 52, 54 may be omitted.
[0197] The operation of the apparatus 10 will now be described,
with reference to both FIGS. 1 and 2.
[0198] The apparatus 10 is initially configured in the disabled
configuration, as show in FIG. 1, and secured to both the drilling
assembly 14 and the drill string 20. A bore may then be drilled,
with weight and torque being transmitted through the apparatus 10
to the drilling assembly 14.
[0199] If the drilling assembly 14 should become stuck within the
bore, for example due to collapse of the bore, the apparatus 10 may
then be reconfigured to the jarring configuration, as in FIG. 2. In
this respect, tension may be established within the drill string
20, for example by pulling upwardly from surface, to thus apply an
axial force between the first and second jarring portions 22, 24,
with the second jarring portion 24 providing a reaction to this
axial force by being rigidly secured to the stuck lower drilling
apparatus 14.
[0200] The applied axial force will initially cause the spring
member 46 to become compressed between the shoulder 42 and the
release ring, permitting energy to become stored within the entire
system. Once the axial force reaches a predetermined magnitude, the
keys 48 of the release ring 44 will be deactivated, thus releasing
the connection between the jarring portions 22, 24, with the stored
energy being released and the upward axial force applied by the
drill string 20 causing the upper jarring portion 22 to move
upwardly relative to the lower jarring portion 24 at a relatively
high velocity until the surfaces 32, 38 of the respective impact
members 30, 36 impact each other, generating an impact force
therebetween. This initial impact force may function to jar the
stuck drilling assembly 14, and contribute towards freeing this.
This upward movement of the upper jarring portion 22 also
disengages the splines 52, 54 of the rotary connection arrangement
50, permitting the jarring portions 22, 24 to become rotatably
decoupled. However, as noted above, the keys 48 may alternatively
provide a rotary coupling, such that release of the keys 48 also
releases the rotary coupling.
[0201] Once the apparatus 10 is configured in this jarring
configuration, and if the initial jarring force generated by
initial impact of the impact members 30, 36 did not free the
drilling assembly 14, tension is applied to the drill string 20 to
pull on the upper jarring portion 22 and press the impact surfaces
32, 38 together, and the drill string 20 also rotated to rotate the
upper jarring portion 22 relative to the lower drilling portion 24.
This relative rotation establishes rotating sliding engagement of
the surfaces 32, 38, such that interaction of the teeth 34, 40
causes the surfaces 32, 38 to continuously be separated and
reengaged, thus establishing a repeated impact force therebetween,
which will providing jarring to the stuck drilling assembly 14
through the lower jarring portion 24. This jarring may effectively
assist to free the drilling assembly 14.
[0202] The apparatus 10 further comprises a clutch arrangement 55
which includes a clutch member 56 in engagement with the sleeve 28
of the lower jarring portion 24 to establish a drag torque
therebetween. When the lower jarring portion 24 is fixed within the
bore due to engagement with a stuck drilling assembly 14, the drill
string 20 will be will be required to establish a torque which
exceeds the drag torque of the clutch arrangement 55 to establish
rotation of the upper jarring portion 22. If at any time during
relative rotation and jarring between the upper and lower jarring
portions 22, 24 the lower jarring assembly 24 should become free,
for example due to release of the drilling assembly 14, the drag
torque established by the clutch arrangement 55 will permit the
upper and lower jarring portions 22, 24 to be rotatably coupled.
This may therefore permit the drill string 20 to rotate the lower
jarring portion 24 and connected drilling assembly 14, which may
assist in further freeing of the drilling assembly 14, for example
by permitting cleaning or reaming of the bore during this
established rotation.
[0203] In some embodiments, the clutch arrangement 55, or a
separate clutch arrangement (not shown), may provide a releasable
rotary connection between the jarring portions.
[0204] The magnitude of the jarring force achieved may be readily
adjusted by adjusting the axial force applied by the drill string
20. Further, the frequency of jarring may be readily adjusted by
adjusting the rotational velocity of the drill string 20. Such a
level of control of the jarring force and jarring frequency is not
possible with prior art jarring methods.
[0205] This particular jarring arrangement provided by the
apparatus 10 provides a number of advantages. For example, the
ability to generate a jarring force in an axial direction by
interaction of the teeth 34, 40, in combination with the
application of a near constant uni-axial loading on the stuck
portion by the drill string 20, improves the effect of the
apparatus 10 to free the drilling apparatus 14.
[0206] Also, the ability to generate a repeated jarring force will
permit higher jarring frequencies to be achieved in relation to
prior art methods. The ability to generate a higher jarring
frequency may permit the apparatus 10 to impart vibration to
associated equipment, such as the drilling assembly 14. In this
respect, a higher jarring frequency or application of a vibratory
force to any solid particulate which is in contact with the
apparatus 10, drill string 20 or drilling assembly 14, for example
due to collapse of the surrounding bore, may result in a condition
termed `Solid Particulate Liquefaction`. This phenomenon
essentially converts the behaviour of the solid particles to that
of a liquid, reducing the shear strength of the solid and allowing
the apparatus or associated object or equipment to be more readily
freed from any bind with the solid particles.
[0207] Furthermore, the ability to apply higher frequency jarring
may improve the ability to address any stick-slip bind between an
object and a bore wall or collapsed bore wall.
[0208] Also, the ability to readily vary the jarring frequency by
controlling the rotational velocity of the drill string 20 may
permit the drilling assembly 14, for example, to be vibrated at its
resonant or natural frequency (or a selected preferred harmonic
frequency). This may allow the delivery of impact loading to far
higher levels than would be achievable using conventional jars, yet
with significantly reduced input forces. Further, when vibrating at
resonant or a harmonic frequency, the drilling assembly 14, which
may be elongate in nature, may be caused to oscillate (wobble) in a
sinusoidal wave pattern within the bore which may assist in
addressing certain sticking phenomenon within the ore, such as
differential sticking.
[0209] In some embodiments the apparatus 10 may be provided in
combination with a live active monitoring system 60 to permit any
resonant behaviour to be monitored and allow adjustment of the
jarring frequency and/or magnitude accordingly.
[0210] In the present embodiment the apparatus 10 may be resettable
such that drilling may be continued following a successful jarring
operation. For example, when the drilling assembly 14 has become
free, this may be engaged with the bottom of the bore and weight
applied via the drill string 20 to thus move the upper jarring
portion 22 downwardly relative to the lower portion 24 until the
keys 48 of the release ring 44 reengage with the sleeve 28 to
re-establish the axial connection, and until the splines 52, 54
interengage, thus re-establishing the rotary connection. As noted
above, in some embodiments the releasable connection may
alternatively or additionally be achieve by the keys 48 and/or a
clutch.
[0211] The ability to reset the apparatus may not only permit
drilling to continue, but may also facilitate multiple initial jars
to be achieved.
[0212] In the embodiment described above, the impact surfaces 32
and 38 form part of the rotatable jarring arrangement 37 in that
the sliding interaction of the impact surfaces results in
generation of jarring force. However, the impact surfaces could be
configured separately or remotely from the rotatable jarring
arrangement such that the impact surfaces generate the jarring
force by responding to axial translation provided by a separate or
remote jarring arrangement. In such a modification, the impact
surfaces could be planar.
[0213] FIGS. 3a and 3b illustrate a part-sectional diagrammatic
view of an alternative embodiment of a jarring apparatus 110 which
is provided with a rotatable jarring arrangement 137 which
comprises a mechanism for effecting axial movement which is
different to the aforementioned rotatable jarring arrangement 37 of
FIGS. 1 and 2. The rotatable jarring arrangement 137 is interposed
between first and second jarring portions of the apparatus 110.
[0214] The apparatus comprises first and second impact surfaces
158, 160 and the rotatable jarring arrangement 137 is positioned
remotely from the impact surfaces. A slot 162 is defined by a
region between a first surface profile 164 and a second surface
profile 168. The surfaces 162, 166 shown in FIG. 3a accommodate a
engaging member 170 therebetween, wherein impact members 130, 136
are shown configured to be separated axially, as depicted by arrow
171. The engaging member 170 is connected to rotating axle 172
which effects rotating drive movement upon engaging member 170.
Rotation of engaging member 170 within the slot 162 results in
relative axial movement of the impact members 130, 136, wherein the
impact surfaces 158, 160 are impacted together in a direction
indicated by arrow 173 to generate an impact force therebetween, as
shown in FIG. 3b. Further rotation of engaging member 170 results
in separation of impact surfaces 158, 160, and if necessary further
subsequent impact of impact surfaces 158, 160 upon further relative
rotation of engaging member 170 and the additional surfaces 162,
166.
[0215] During use, impact members 130, 136 impact together
according to movement of the engaging member within the slot 162.
In the presently envisaged embodiment the engaging member 170 is in
contact with both additional surfaces 162 and 166. However, only
one additional surface needs to be in engagement with the engaging
member 170, for example, in this embodiment only the additional
surface 166 may be engaged with uneven surface profile 168 as
impact member 130 would be pushed against additional surface 166
when held under tension provided by a drilling assembly (not shown
in the present embodiment) and drill string (not shown in the
present embodiment). In other embodiments the converse may provide
the appropriate engagement between either of additional surfaces
162 or 166 and engaging member 170. In an alternative embodiment
(not shown) the apparatus may include co-operating annular members
in place of the engaging member 162.
[0216] FIGS. 4a to 4c illustrate part-sectional diagrammatic views
of an alternative embodiment of a jarring apparatus 210 which is
provided with a pressurising mechanism for effecting axial movement
of the first and second impact surfaces. FIGS. 4a to 4c show
different stages of operation during use of the jarring apparatus
described in the second additional embodiment.
[0217] The apparatus 210 comprises a housing 273 comprising first
and second impact members 230, 236. The first impact member 230
separates first and second fluid reservoirs 274, 276. The second
impact member 236 axially encloses the second fluid reservoir 276
with first and second impact surfaces 258, 260 disposed
therebetween. A pump 278, for example, a progressive cavity pump,
is disposed between the first and second fluid reservoirs and
configured to communicate actuating fluid from the first fluid
reservoir 274 to the second fluid reservoir 276 upon relative
rotation of the pump 278 and the first impact member 236. The
relative rotation of the pump 278 and first impact member 236 is
achieved by rotation of a rotating drive movement, thereby
transferring actuating fluid from the first fluid reservoir 274 to
the second fluid reservoir 276 in a direction generally indicated
by arrows 279. A channel 280 is provided between first and second
fluid reservoirs 274, 276 to provide communication of actuating
fluid therebetween. Actuating fluid is communicated from the second
fluid reservoir 276 to the first fluid reservoir 274 through
channel 280 in a direction indicated by arrow 282 in FIG. 4b.
Communication of fluid using channel 280 is selectively provided
using valve 284.
[0218] The communication of actuating fluid from the first fluid
reservoir to the second fluid reservoir results in an increase in
fluid pressure in the second fluid reservoir which results in the
axial separation of the second impact surface 260 relative to the
first impact surface 258 in a direction indicated by arrow 286 in
FIG. 4a.
[0219] A valve 284 prevents communication of actuating fluid via
channel 280. A limit trigger 288 is provided to define a threshold
beyond which de-pressurisation of the second fluid reservoir occurs
due the valve 284 permitting actuating fluid communication from the
second fluid reservoir 276 to the first fluid reservoir 274 via
channel 280. The limit trigger 288 may be activated upon reached a
mechanical limit in terms of relative separation of the impact
members, a pressure limit or the like. In the embodiment shown the
valve 284 is activated or de-activated through a trigger system
comprising a trigger member 292, trigger spring 294 which are
connected via trigger connector 296 to rotate the valve 284 to
permit or prevent actuating fluid communication through channel
280. Alternative valve or channel arrangements may be envisaged
whose pressurisation and de-pressurisation functions are equivalent
to the embodiment described herein.
[0220] FIGS. 4a to 4c illustrate a sequence of events within a
cycle of pressurisation and de-pressurisation of the apparatus.
FIG. 4a illustrates pressurisation of the second fluid reservoir,
thereby axially separating the first and second impact members.
FIG. 4b illustrates the impact members at their maximum axial
separation, as defined by the trigger limit 288, upon reaching
which the valve 284 permits communication of actuating fluid from
the second fluid reservoir 276 to the first fluid reservoir 274 via
channel 280. Valve 284 may be configured to permit communication of
actuating fluid for a pre-defined unit of time. Tension provided
between the first and second jarring portions results in rapid
de-pressurisation of the second fluid reservoir 276 to permit axial
engagement of the first and second impact surfaces, and hence
impact therebetween. Subsequent to the impact of the impact
surfaces, the valve 284 closes to permit subsequent
re-pressurisation of the second fluid reservoir 276.
[0221] FIGS. 4a to 4c are representative of a cycle of
pressurisation and de-pressurisation events to generate a jarring
effect. Multiple jar events could be generated by cyclically
operating the apparatus. Alternative configurations of the
apparatus described herein could be conceived to equivalently
generate the jarring effect.
[0222] FIGS. 5a to 5b illustrate part-sectional diagrammatic views
of an alternative embodiment of a jarring apparatus 310 which is
provided by a rotating jarring arrangement 337 which comprises a
rotating lobe arrangement for effecting relative axial movement of
the first and second impact surfaces. FIG. 6a shows an axial view
of the rotating jarring arrangement 337 and FIG. 6b (i)-(iv) show
representative side views of the rotating jarring arrangement
during a rotational cycle of the apparatus.
[0223] In reference to FIGS. 5a and 5b the apparatus 310 comprises
a first impact member 330, which is associated with one of the
first or second jarring portions, and second impact member 336,
which is associated with the other of the first or second jarring
portions. First impact member 330 comprises a first impact surface
358. Second impact member 336 comprises a second impact surface
360. The rotating jarring arrangement 337 is rotated by a rotating
drive movement directed through axle 372, which effects rotation of
rotating lobe arrangement 398. Rotating lobe arrangement 398
comprises at least one lobe 3100, which rotates about a radially
extending axis 3102. In the depicted embodiment there are provided
a plurality, namely two, of lobe 3100, as shown in FIG. 5b.
Rotating lobe arrangement 398 is housed in an accommodating region
3104, which is axially remote from the impact members 330 and 336.
The accommodating region 3104 comprises upper contact surface 3106
and lower contact surface 3107. In the present embodiment, the
upper contact surface 3106 of the accommodating region 3104 is
maintained in engagement with a circumferential position on lobe
contact surface, for example, shown by 3108 in FIG. 5a and 3110 in
FIG. 5b. Rotating drive movement of the rotating lobe arrangement
398 translates the lobe 3100 in a circumferential path while in
engagement with upper contact surface 3106. During translation in
the circumferential path, frictional force applied between lobe
3100 and upper contact surface 3106 results in subsequent rotation
of the lobe 3100 about the radially extending axis 3102. The lobe
3100 are configured to effect relative axial movement of the first
and second impact surfaces 358 and 360 via axle 372 upon rotation
of the lobes 3100 relative to upper contact surface 3106.
[0224] In reference to FIGS. 6a and 6b (i)-(iv) to support FIGS. 5a
and 5b, different partial views of the apparatus 310 are shown. The
first impact surface 358 is shown in its maximum axial separation
from second impact surface 360 in FIG. 5a, as indicated by
direction arrow 3112. Upon subsequent rotation of the rotating lobe
arrangement 398, the impact surfaces are shown at or during impact
in FIG. 5b, as depicted by direction arrow 3114. Axial rotation
3116 of the rotating lobe arrangement 398 is depicted in FIG. 6a. A
cycle of lobe rotation is shown in FIG. 6b (i)-(iv) in which the
lobe 3100 is shown during a cycle of rotation. Tension applied via
the first and second jarring portions stores energy within the
apparatus such that when the lobe in shown to provide maximum
impact surface separation, as indicated in FIG. 6b (iii) and
indicated by arrow 3118, subsequent rotation of the lobe, as in
FIG. 6b (iv) the rotation of lobe 3100 causes relative rapid axial
movement of the impact in a direction depicted by arrow 3120 in
FIG. 6b (iv).
[0225] It should be understood that tension applied to the
apparatus via the work string plays an important part in defining
the amplitude of impact between first and second impact surfaces in
that the resulting stored energy increases impact force
therebetween. In an alternative embodiment the lobe 3100 may be
configured to be in contact with lower contact surface 3107. In an
alternative embodiment the coefficient of friction between the lobe
3100 and lobe contact surface may be adjusted to permit sliding
engagement therebetween such that the rotating lobe arrangement 398
remains rotationally static with rotation of the lobes about the
radially extending axis being actuated by a differential mechanism,
which is rotated by a rotating drive movement derived from the
central axis of the jarring apparatus, thereby maintaining its
definition as a rotary jarring apparatus.
[0226] It should be understood that the embodiments described
herein are merely exemplary and that various modifications may be
made thereto without departing from the scope of the invention. For
example, any suitable mechanism may be utilised which can translate
a rotational drive movement to an axial impact movement of impact
surfaces. As such, axial impact may be controlled and initiated by
a rotary action or drive. Further, the jarring apparatus is not
exclusively for use in drilling applications, and may be used in
any application in which an object requires jarring in a bore.
* * * * *